Snorkel mask



FIG. 1 is a front perspective view of a snorkel mask showing my new design;

FIG. 2 is a left side perspective view thereof, with the right side perspective view being a mirror image;

FIG. 3 is a front perspective view thereof; and,

FIG. 4 is a back perspective view thereof.

The broken lines in the drawings depict portions of the snorkel mask that form no part of the claimed design. 

CLAIM The ornamental design for a snorkel mask, as shown and described. 